The present invention relates to the shaping of glass sheets, and particularly to the shaping of glass sheets to relatively deep shapes by press bending and especially to glass sheets that have a coated surface portion defining either a decorative area or an electroconductive heating circuit or an opaque covering over a marginal area where an automobile window is bonded to an automobile frame.
The use of bent glass sheets has increased in recent years. Automobiles are provided with one piece bent windshields and also with one piece bent and tempered rear windows. In recent years, rear windows (also termed backlights) have been provided with heating circuits of electroconductive material applied to the inner surface of the rear window that help remove frost and ice deposits on the window by subjecting the circuit to an electrical voltage.
To fabricate bent and tempered glass sheets for certain patterns of continuous rear windows of automobiles or as one of the components of a laminated windshield, glass sheets are supported in a vertical or oblique position, either by suspending the glass from tongs or supporting the glass along its bottom edge and balancing the glass sheet either by mechanical balancing means near its upper edge in a near vertical orientation or by fluid or gas directed against or parallel to one or more major surfaces of an oblique glass sheet.
The glass sheets are shaped to the desired shape by press bending a sheet after it has been heated to a temperature sufficient for the glass to deform readily. After a glass sheet is shaped, it is removed from a shaping station and transported into a cooling station where the glass sheet is chilled in a cold tempering medium such as blasts of cold air applied against the opposite major surfaces of the glass sheet to cool the glass sheet at a cooling rate sufficient to impart a desired degree of temper in the glass sheet.